Simple circuit - Where is current going?

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AI Thread Summary
The discussion revolves around finding the voltage at node Va in a circuit involving resistors. Participants clarify that the circuit is not a simple voltage divider due to the presence of multiple resistors and that the voltage at Va is measured relative to ground. There is confusion regarding the flow of current through resistor R2 and the implications of using Kirchhoff's Current Law (KCL) at the node. It is emphasized that current conservation must be applied at the node where currents from R1 and R2 converge. The conversation highlights the importance of understanding circuit configurations and the reference points for voltage measurements.
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Homework Statement



Find the voltage at Va.

Homework Equations



Ohm's Law, Current Divider, etc
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The Attempt at a Solution


This is the almost identical to the cookie cutter voltage divider, except that there is a resistor on the output. I'm curious if current would even flow through R2. I guess when you are asked for the voltage at a specific node, it is implied that the common is on ground. So in this case, is the answer going to be the voltage drop between Va and ground? Which might would be R2 and R3 in parallel? or something. I'm very confused.
 
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Brilliant said:
This is the almost identical to the cookie cutter voltage divider, except that there is a resistor on the output.

No, not really a voltage divider (no two resistors are in series here). And what have you defined as the output?
Brilliant said:
I'm curious if current would even flow through R2.

Why wouldn't it?

Brilliant said:
I guess when you are asked for the voltage at a specific node, it is implied that the common is on ground.

I'm not sure what you mean by "the common", but ground is the reference point relative to which all potentials are measured, yes.

Brilliant said:
So in this case, is the answer going to be the voltage drop between Va and ground?

Yes, voltage VA is defined as the potential difference between the point in the circuit that is labelled VA and ground.

Brilliant said:
Which might would be R2 and R3 in parallel? or something. I'm very confused.

I can't make sense of this, grammatically or otherwise.

Just use KCL at the node where you've hand-drawn the dot. Assume that some of the current comes into this node from the left (across the branch with R1) and some comes into this node from the right (across the branch with R2). KCL says charge is conserved (can't just disappear) therefore all of the current flowing into this node (the sum of the two currents from either side) is equal to the current flowing out of it (which is across the branch with R3).
 
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